Nationally recommended sorghum planting dates in South Africa are inaccurate since they are similar for all sorghum growing regions, irrespective of climatic and soil variations within agro-ecological regions The objective was to apply a well–calibrated and tested AquaCrop model to formulate optimal planting dates and best practice management recommendations for rainfed sorghum production in three different agro–ecologies of KwaZulu–Natal, South Africa (Ukulinga, Deepdale, and Richards Bay). The FAO AquaCrop model was used to generate 10 planting dates for the different agro–ecologies. Crop files for two sorghum genotypes Ujiba (landrace) and PAN8816 (hybrid) were used for model simulations, where 10 year historical climate data was considered. Seasonal rainfall, amount of soil evaporation, crop transpired water, and ground canopy cover were identified as key parameters influencing sorghum biomass, yield and water productivity. The following optimal dates were identified at Ukulinga (7 September - 24 November), Richards Bay (23 December - 3 January), and Deepdale (21 December - 3 January). These were recommended to update generic national recommendations for sorghum for agro-ecologies represented by the respective sites. High soil evaporation relative to transpiration in all agro-ecologies indicated that the low hanging fruit in improving sorghum yields was strategies use of strategies that reduce soil evaporation and increase soil water retention. Further research can look at calibrating and validating AquaCrop for best practice management recommendations suggested in this study to predict with accuracy the impact of such strategies on yield and water productivity of sorghum in various agro-ecologies.

南非国家推荐的高粱种植日期不准确，因为与所有高粱生长地区的种植日期相似，无论农业生态区域内的气候和土壤变化如何，目的都是应用经过良好校准和测试的AquaCrop模型来制定最佳种植日期和南非夸祖鲁-纳塔尔省（Ukulinga，Deepdale和Richards Bay）三种不同农业生态中雨养高粱生产的最佳实践管理建议。粮农组织的AquaCrop模型用于为不同的农业生态系统生成10个播种日期。两种高粱基因型Ujiba（地方品种）和PAN8816（杂种）的作物文件用于模型模拟，其中考虑了10年的历史气候数据。季节性降雨，土壤蒸发量，农作物蒸发的水，冠层和地面冠层被确定为影响高粱生物量，产量和水分生产率的关键参数。在Ukulinga（9月7日至11月24日），Richards Bay（12月23日至1月3日）和Deepdale（12月21日至1月3日）确定了以下最佳日期。建议对这些文件进行更新，以更新各自地点代表的关于农业生态的高粱通用国家建议。与所有农业生态系统中的蒸腾作用相比，较高的土壤蒸发量表明，提高高粱产量的低挂果是减少土壤蒸发量和增加土壤保水量的策略。